Brian F. Allen

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Three reported cases of fractures in teenagers of the medial clavicle associated with a posterior disruption at the sternoclavicular joint have similar findings. The medial fragment is rotated 90 degrees to the coronal plane. The medial fragment is usually stripped of its periosteum. Treatment requires open reduction and internal fixation of the clavicle(More)
Fluid bipedal locomotion remains a significant challenge for humanoid robotics. Recent bio-inspired approaches have made significant progress by using small numbers of tightly coupled neurons, called central pattern generators (CPGs). Our approach exchanges complexity of the neuron model for complexity of the network, gradually building a network of simple(More)
Despite technological advances in the tracking of surgical motions, automatic evaluation of laparoscopic skills remains remote. A new method is proposed that combines multiple discrete motion analysis metrics. This new method is compared with previously proposed metric combination methods and shown to provide greater ability for classifying novice and(More)
We propose a method for accurately tracking the spatial motion of standard laparoscopic instruments from video. By exploiting the geometric and photometric invariants common to standard FLS training boxes, the method provides robust and accurate tracking of instruments from video. The proposed method requires no modifications to the standard FLS training(More)
Dynamic simulation is a promising complement to kinematic motion synthesis, particularly in cases where simulated characters need to respond to unpredictable interactions. Moving beyond simple rag-doll effects, though, requires dynamic control. The main issue with dynamic control is that there are no standardized techniques that allow an animator to(More)
We introduce a toolkit for creating dynamic controllers for articulated characters under physical simulation. Our toolkit allows users to create dynamic controllers for interactive or offline use through a combination of both visual and scripting tools. Users can design controllers by specifying keyframe poses, using a high-level scripting language, or by(More)
We present a system for automatically evolving neural networks as physics-based locomotion controllers for humanoid characters. Our approach provides two key features: (a) the topology of the neural network controller gradually grows in size to allow increasingly complex behavior, and (b) the evolutionary process requires only the physical properties of the(More)
We present a technique that simulates wet garments for virtual humans with realistic folds and wrinkles. Our approach combines three new models to allow realistic simulation of wet garments: (1) a simplified saturation model that modifies the masses, (2) a nonlinear friction model derived from previously reported, real-world measurements, and (3) a wrinkle(More)
We describe in this paper a training system for minimally invasive surgery (MIS) that creates an immersive training simulation by recording the pathways of the instruments from an expert surgeon while performing an actual training task. Instrument spatial pathway data is stored and later accessed at the training station in order to visualize the ergonomic(More)